551812218161 has 2 divisors, whose sum is σ = 551812218162. Its totient is φ = 551812218160.

The previous prime is 551812218119. The next prime is 551812218163. The reversal of 551812218161 is 161812218155.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 338212033600 + 213600184561 = 581560^2 + 462169^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-551812218161 is a prime.

It is a super-2 number, since 2×551812218161² (a number of 24 digits) contains 22 as substring.

Together with 551812218163, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (551812218163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275906109080 + 275906109081.

It is an arithmetic number, because the mean of its divisors is an integer number (275906109081).

Almost surely, 2^551812218161 is an apocalyptic number.

It is an amenable number.

551812218161 is a deficient number, since it is larger than the sum of its proper divisors (1).

551812218161 is an equidigital number, since it uses as much as digits as its factorization.

551812218161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38400, while the sum is 41.

The spelling of 551812218161 in words is "five hundred fifty-one billion, eight hundred twelve million, two hundred eighteen thousand, one hundred sixty-one".